1. Field of the Invention
The present invention relates to a portable terminal. More particularly, the present invention relates to a sliding-type portable terminal, in which a pair of housings is coupled with each other in such a manner that they can linearly move while facing each other.
2. Description of the Related Art
In general, the term “portable terminal” refers to a device that provides a user with a mobile communication function. With the advancement of technology, portable terminals now include complex functions so as to be used as a multimedia device for playing a music file, a moving picture file, and the like and for use as a financial service device for making a micro payment, mobile banking, and the like, in addition to a simple mobile communication device.
Portable terminals may be classified into bar-type terminals, flip-type terminals and folder-type terminals according to their appearance. Recently, sliding-type terminals have also been released. The sliding-type terminals occupy a dominant position in the portable terminal market, together with the folder-type terminals.
The bar-type portable terminal has a single body housing on which a keypad, an input unit such as a transmitter, a display unit, and an output unit such as a receiver, are mounted. Although every unit used for the mobile communication function is mounted on the single body housing so that the terminal is simple, there is a limitation in the miniaturization of the portable terminal because it is difficult to secure a distance between the transmitter and receiver.
The flip-type portable terminal has a flip cover rotatably assembled with a bar-type portable terminal so as to cover the keypad used as the input unit in the communication-standby mode. Such configuration prevents the inadvertent function of the keypad. However, there is also a limitation in the miniaturization of the flip-type portable terminal because it is difficult to secure a distance between the transmitter and the receiver.
The folder-type portable terminal includes a pair of body housings assembled so as to be folded. As a transmitter and a receiver are arranged on each of the pair of body housings, respectively, it is preferable to make the terminal compact and is easy to secure a sufficient distance between the transmitter and the receiver. Thus, the folder-type portable terminal has occupied a dominant position in the portable terminal market for some time.
The sliding-type portable terminal has a pair of housings assembled to be slidable. In a sliding-type portable terminal, an input unit and an output unit are separately mounted on each of the pair of housings. More particularly, the keypad, which is an input unit, is opened/closed according to the sliding direction of the housings. Accordingly, an inadvertent function of the keypad is prevented in the standby state, it is convenient to use in the call state and it advantageously makes the terminal compact. Because of these advantages, the sliding-type portable terminal has gradually gained larger portions of the overall market of portable terminals so that now it occupies a more dominant position than that of the folder-type portable terminal.
However, in the sliding-type portable terminal, the sliding range is limited in order to secure a firm assembling structure. For example, in a sliding-type portable terminal having a total length of 90˜100 mm in a state of a pair of housings being opened, the slidable range of one housing in a longitudinal direction is limited to approximately 35 mm. That is, when one housing of the terminal slides so as to open a part of the other housing, the two housings maintain a closed state of a minimum of 55 mm.
The above-described sliding-type portable terminal has a problem in that it is difficult to a secure a sufficient space for mounting the input unit, particularly the keypad. In order to solve the problem, a keypad for inputting a character/number and a keypad including functional keys such as a menu item key, a call key, or the like, are provided so that each is mounted on a different housing, respectively. However, that disadvantageously makes the space for mounting the display unit smaller.